Day 1!

2 files changed, 50 insertions, 13 deletions

diff --git a/lib/src/error.rs b/lib/src/error.rs
index cd4a760..216df78 100644
--- a/lib/src/error.rs
+++ b/lib/src/error.rs
@@ -1,30 +1,41 @@
 #[derive(Debug)]
 pub enum Error {
-    IO(std::io::Error),
+  IO(std::io::Error),
+  Parse,
 }
 
 impl std::error::Error for Error { }
 
 impl std::fmt::Display for Error {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            Error::IO(e) => e.fmt(f),
-        }
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    match self {
+      Error::IO(e) => e.fmt(f),
+      Error::Parse => f.write_str("Parse error"),
     }
+  }
 }
 
 impl std::cmp::PartialEq for Error {
-    fn eq(&self, other: &Self) -> bool {
-        match (self, other) {
-            (Error::IO(_), Error::IO(_)) =>
-                false,
-        }
+  fn eq(&self, other: &Self) -> bool {
+    match (self, other) {
+      (Error::IO(_), Error::IO(_)) =>
+        false,
+      (Error::Parse, Error::Parse) =>
+        true,
+      _ =>
+        false,
     }
+  }
 }
 
 impl From<std::io::Error> for Error {
-    fn from(e: std::io::Error) -> Error {
-        Error::IO(e)
-    }
+  fn from(e: std::io::Error) -> Error {
+    Error::IO(e)
+  }
 }
 
+impl From<std::num::ParseIntError> for Error {
+  fn from(_: std::num::ParseIntError) -> Error {
+    Error::Parse
+  }
+}
diff --git a/lib/src/lib.rs b/lib/src/lib.rs
index b198f10..4b4b679 100644
--- a/lib/src/lib.rs
+++ b/lib/src/lib.rs
@@ -3,9 +3,35 @@ pub mod prelude;
 
 pub use crate::prelude::Result;
 
+use std::fs::File;
+use std::io::BufReader;
+use std::io::prelude::*;
+
 
 pub fn greeting() -> Result<()> {
   println!("Hello, Irenes!");
 
   Ok(())
 }
+
+pub fn read_int_file(filename: &str) -> Result<Vec<i64>> {
+  let file = File::open(filename)?;
+  let mut reader = BufReader::new(file);
+  let mut buffer = String::new();
+
+  let mut input: Vec<i64> = Vec::new();
+  loop {
+    reader.read_line(&mut buffer)?;
+    if buffer.len() == 0 {
+      break;
+    }
+
+    let item = buffer.trim().parse::<i64>()?;
+
+    buffer.clear();
+
+    input.push(item);
+  }
+
+  Ok(input)
+}